The state of the art, in the rendering by visual artists, of human expression is set forth in Gary Fagin, The Artist's Complete Guide to Facial Expression, Watson-Guptill Publications, New York 1990 (hereinafter referred to as "Fagin"). The state of the art in computer animation of faces is set forth in F. Parke and K. Waters, Computer Facial Animation, A. K. Peters, Wellesley, Mass. (1996) (hereinafter referred to as "Parke et al.") and in the references cited therein. The foregoing references are hereby incorporated herein by reference.
The present state of computer animation has now enabled the representation of gross expression gestures, but not the convincing representation of human expression that is mastered implicitly by visual artists such as taught in Fagin.